Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Wed, 18 Jan 2023 11:48:44 +0100 | Subject | Re: [PATCH v2 1/2] riscv: Add instruction dump to RISC-V splats |
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Hi Björn,
On Mon, Jan 16, 2023 at 8:41 AM Björn Töpel <bjorn@kernel.org> wrote: > From: Björn Töpel <bjorn@rivosinc.com> > > Add instruction dump (Code:) output to RISC-V splats. Dump 16b > parcels. > > An example: > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 > Oops [#1] > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc3-00302-g840ff44c571d-dirty #27 > Hardware name: riscv-virtio,qemu (DT) > epc : kernel_init+0xc8/0x10e > ra : kernel_init+0x70/0x10e > epc : ffffffff80bd9a40 ra : ffffffff80bd99e8 sp : ff2000000060bec0 > gp : ffffffff81730b28 tp : ff6000007ff00000 t0 : 7974697275636573 > t1 : 0000000000000000 t2 : 3030303270393d6e s0 : ff2000000060bee0 > s1 : ffffffff81732028 a0 : 0000000000000000 a1 : ff60000080dd1780 > a2 : 0000000000000002 a3 : ffffffff8176a470 a4 : 0000000000000000 > a5 : 000000000000000a a6 : 0000000000000081 a7 : ff60000080dd1780 > s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 > s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 > s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 > s11: 0000000000000000 t3 : ffffffff81186018 t4 : 0000000000000022 > t5 : 000000000000003d t6 : 0000000000000000 > status: 0000000200000120 badaddr: 0000000000000000 cause: 000000000000000f > [<ffffffff80003528>] ret_from_exception+0x0/0x16 > Code: 862a d179 608c a517 0069 0513 2be5 d0ef db2e 47a9 (c11c) a517 > ---[ end trace 0000000000000000 ]--- > Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > SMP: stopping secondary CPUs > ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- > > Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Thanks for your patch!
> --- a/arch/riscv/kernel/traps.c > +++ b/arch/riscv/kernel/traps.c > @@ -29,6 +29,27 @@ int show_unhandled_signals = 1; > > static DEFINE_SPINLOCK(die_lock); > > +static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs) > +{ > + char str[sizeof("0000 ") * 12 + 2 + 1], *p = str; > + unsigned long addr = regs->epc;
Given you never use this as an unsigned long, what about
const u16 *insns = (u16 *)instruction_pointer(regs);
so you no longer need casts below?
> + long bad; > + u16 val; > + int i; > + > + for (i = -10; i < 2; i++) { > + bad = get_kernel_nofault(val, &((u16 *)addr)[i]); > + if (!bad) { > + p += sprintf(p, i == 0 ? "(%04hx) " : "%04hx ", val); > + } else { > + printk("%sCode: Unable to access instruction at 0x%lx.\n",
%px, so you can drop the cast to long below.
> + loglvl, (long)&((u16 *)addr)[i]); > + return; > + } > + } > + printk("%sCode: %s\n", loglvl, str); > +} > + > void die(struct pt_regs *regs, const char *str) > { > static int die_counter;
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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